Oral creatine supplementation can acutely ameliorate skeletal muscle function in older humans, but its value in the prevention of sarcopenia remains unknown. We evaluated the effects of lifelong creatine supplementation on muscle mass and morphology, contractility and metabolic properties in a mouse model of muscle senescence. Male senescenceaccelerated mice (SAMP8) were fed control or creatine-supplemented (2% of food intake) diet from the age of 10 to 60 weeks. Soleus and EDL muscles were tested for in vitro contractile properties, creatine content and morphology at week 25 and 60. Both muscle types showed reduced phosphocreatine content at week 60 that could not be prevented by creatine. Accordingly, age-associated decline in muscle mass and contractility was not influenced by treatment. Aged soleus muscles had fewer and smaller fast-twitch glycolytic fibers irrespective of treatment received. It is concluded that lifelong creatine supplementation is no effective strategy to prevent sarcopenia in senescence-accelerated mice.